Sealing means for rotary pumps



June 3, 1 924. 1,496,222

E. HILL SEALING MEANS FOR ROTARY PUMPS Filed May 1, 1923 '2 Shee1sSheet 1 IN VENTOR I zw A TTORNE Y June 3, 1924. 1,496,222

E. HILL SEALING MEANS FOR ROTARY PUMPS Filed May 1, 1923 2 Sheets-Sheet 3 A TTOPNFV Patented June 3, 1924.

ED STATE PATENT OFFICE.

EBENEZER HILL, OF SOUTH NORWALK, CONNECTICUT, ASSIGNOR TO THE HILL COM- PRESSOR & PUMP COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

SEALING MEANS FOR ROTARY PUMPS.

Application filed May 1,

To all whom it may concern.

Be it known that I, EBENEZER HlLL, a citizen of the United States, residing at South Norwalk, in the county of Fairfield and State of Connecticut, have invented a new and useful Improvement in Sealing Means for Rotary Pumps, of which the following is a specification.

This invention relates to a rotary-pump, compressor or similar apparatus, of the type in which there are one or more series of coacting rotary elements for pumping or compressing fluids.

The object of the invention is to provide a construction for apparatus of this class in which the discharge pressure of the fluid is utilized to eflect the scaling of the pumping elements.

This object is attained by assembling a plate, having intake and discharge portsproperly located with relation to the intake and'compression spaces of the pumping elements, in the pumping chamber in juxtaposition to the side faces of the pumping elements under such conditions that the dis charge pressure of the fluid will be exerted on the back of the plate and force it, according to the degree of the discharge pressure, against the faces of the pumping elements and thereby eliminate any possible .leakage of fluid across the faces of and around the outside of the pumping elements.

In the accompanying drawings Fig. 1 shows a central longitudinal section of a single stage pump that embodies this invention. Fig. 2 shows an edge View of the ported sealing plate. Fig. 3 shows a face view of the sealing plate. Fig. 4c is a View similar to Fig. 1, of a two stage pump containingthe invention. I

The single stage pump illustrated has a cylindrical casing 5 with a head 6 that may be removed to give access to the interior of the casing. Extending centrally of the head is a hub 7 with a packing gland 8. In the side of the casing is an intake opening 9 and in the end face of the casing is 'a. discharge opening 10.

In the cylindrical chamber in the casing are two pumping elements, which, in the construction illustrated, are in the shape of an outer driving gear 11 and an inner driven gear 12. The inner gear has external teeth, and the outer gear has internal teeth which are cut in a ring 13 that is fitted tightly the discharge opening of the casing. T e

rim of the outer gear body is shaped so that it will have a close but rotatable fit within the chamber in the casing and the end face of this outer gear is preferably made solid.

The driving shaft 14 is attached to the back or end face of the body of the outer gear and extends through the hub of the casing head, being mounted on anti-friction bearings 15 and made tight by a suitable packing 16 in the gland in the hub. The inner gear is mounted on an arbor 20 with interposed anti-friction bearings 21, and this arbor in the single stage machine illustrated extends into and is supported by the sealing plate 22. The axis of the arbor is eccentric to the axis of the driving shaft, consequently the axis of the inner gear is eccentric to that of the outer gear.

The circular periphery of the sealing plate is preferably provided with packing rings 23 that snugly fit the circular inner wall of the pumping chamber and form a gas tight joint between the edge of the plate and the casing. On one side of the diameter, in the periphery of the sealing plate is an intake chamber 27. This intake chamber is designed to extend opposite the intake opening throughthe casing, and holes 28 through the side wall of the sealing plate connect the intake chamber with the intake spaces between the pumping elements. On the other side of the diameter the sealing plate has a discharge port 29 whichatfords communication through the plate from the compression spaces between the pumping elements to the discharge opening in the casing. The sealing plate is mounted so that it has a free movement sidewise toward the faces of the pumping elements in order that it may establish a tight engagement with the side faces adjacent to the active sections of the pumping elements. It is preferred to have a space 30 between the back of the plate and the inner end wall of the casing, which space is in communication with the discharge port, in order that the fluid at discharge pressure can enter the space and be exerted against the back of the sealing plate so as to force the plate tightly against the faces of the pumping elements.

In normal operation the pumping elements are rotated clockwise and draw fluid in through the intake opening in the casing and intake chamber in the sealing late, and discharge the fluid through the ischarge port in the sealing plate and discharge opening in the casing. This rotation of the pumping elements tends to impart a corresponding r0- tation to the sealing plate which is forced by the pressure against the faces of the pumping elements. To prevent the rotation of the sealing plate a stud 26 is arranged to extend between the plate and the end wall of the casing. This stud is located on'one side of the center of the sealing'plate and is somewhat loose so that without interfering with the sidewise movement of the plate toward the pumping elements it retains the plate from rotation and keeps the intake and discharge ports in proper relation to the intake and discharge openings in the casing and the intake and compression spaces between the pumping elements. Owing to the eccentric location of the stud, any rotary movement that should be imparted to the sealing plate by the drag of the pumping elements causes the plate to fulcrum on the stud in such manner that the sealing engagement of the periphery of the plate, or

the packing rings therein, with the wallof the chamber in the vicinity of the intake opening would be augmented.

With this construction the discharge pressure produced by the rotation of the pumping gears is utilized to force the sealing plate against the faces of the pumping elements and the friction caused by the rotation of the pumping elements against the sealing plate is used to ensure a ti ht joint between the edge of the plate ad acent to the intake and the casing.

In a multiple stage compressor of this type, such as represented in Fig. 4, the driving shaft 31 is extended through the casing and heads, and attached to it are a plurality of outer drivin gears 32 within which are a plurality of Inner driven gears 33. The pumping elements of each succeeding set are smalleror have less capacity than those of the preceding set and the chambers containing the pumping elements are, of course, correspondingly smaller. In this case the ported sealin plates 34' are free to move sidewise toward .t e faces of the pumping elements under the discharge pressure, but are held from rotation by the eccentrically located fulcrum ins 35. In the multiple sta 0 apparatus t e. fluid is taken in through t e intakeopenin 36 in the casing and intake chamber 37 in the sealing late of the first section, and is dischar ed y the pumping elements through the 'scharge port 38 m mamas the sealing plate and discharge opening 39 in ,I the casing, in the same manner as previously to the intake chamber 41 in the sealing plate and is forced by the pumping elements in the second section through the port 42in the sealing plate and discharge opening 43 in the casing at a higher ressure. Any desired number of these sections may be added, one to the other, in order to step up the fluid pressure to the desired degree, and in each section, when constructed as described, the sealing plate is pressed against the pumping elements with a force proportional to the discharge pressure of the section in which the plate is located.

The invention claimed is 1. A rotary pump comprising a casing having an intake and a discharge, pumping means rotatable in the casing having intake and compression spaces, and a plate having a discharge port, said plate belng laterally movable for effecting a sealing engagement with the pumping means to prevent leakage from the intake and compression spaces and held against rotation for maintaining the correct co-relation of said port with the compression space.

2. A rotary pump comprising a casing having an intake and a discharge, intermeshing pumping gears having intake and compression cavities between the teeth, rotatable in the casing, a laterally movable non-rotatable plate facing against said gears only and covering the cavities between the teeth, means causing said plate to be forced against both of said gears for effecting a sealin engagement therewith and preventing lea age across the gear teeth from one cavity to another, and means for preventing the rotation of said plate.

3. A rotary pump comprising a casing having an intake and a discharge, pumping means rotatable in the casing having intake and compression spaces, a plate within the casing, in juxtaposition to the side faces of the pumping means, r ovided with intake and discharge ports communicating with said spaces, and a pressure chamber between the plate and casing into which compressed fluid from the discharge port enters and exerts pressure on the plate and moves it into sealing engagement with the side faces of the pumping means.

4. A' rotary pump comprising a casing having an intake and a discharge, intermeshing pumping gears having intake and compression cavities between the teeth, rotatable in the casing, a non-rotatable laterally movable plate bearing against said gears only and forming one wall of said cavities, means for directing pressure of fluid discharged from the compression cavities against the back of said plate for forcing said plate against both of the gears, about the cavities pression cavities between the teeth, rotatable in the casing, a plate facing against the gears only and forming one wall of said cavities to prevent leakage from one cavity to another, said plate being forced against the gears by the pressure discharged from the compression cavities, and means permitting of the lateral movement, but preventing the rotation, of said plate.

6. A rotary pump comprising a casing having an intake and a discharge, intermeshing pumping gears having intake and compression cavities between the teeth, rotatable in the casing, a non-rotatable floating plate bearing against the gears only and forming one Wall of said cavities to prevent leaka e from said cavities, said plate being force against both of the gears by fluid pressure discharged from the compression cavities, and packing rings fitted between the perimeter of said plate and the casing.

7. 'A rotary pump COIIIPIISlDg a casing having an intake and a discharge, pumping gears rotatable in the casing having intake and compression spaces, a valve plate coacting with said pumping means to permit gas to enter and pass from said cavities and yet" prevent leakage from one space to another, said plate being free to be pressed against both of the pumping gears by the pressure discharge from' the compression space, and means eccentric to the center of said plate retaining the plate from concentric movement but permitting it to move laterally and eccent-rically with relation to the pumping gears.

8. A rotary pump comprising a casing, pumping means rotatable in the casing, a plate, having intake and discharge ports, laterally movable toward the pumping means to efiect a sealing engagement therewith, and a fulcrum eccentric to the center of the plate between the intake and discharge ports of the plate on the compression .side of the pumping means.

9. A rotary pump comprising a casing having an intake and a discharge, pumping means rotatable in the casing, a plate having intake and discharge ports-correspondingly located with relation to the intake and'discharge of the casing, and a fulcrum eccentric to the center of the plate between the intake and discharge ports of the plate on the compression side of the pumping means for establishing a sealing engagement of the plate and easing around the inlet port of the casing. I

10. A rotary pump comprising a casing having an intake and a discharge, pumping means rotatable in the casing, a plate having intake and discharge ports correspondingly located with relation to the intake and discharge of the casing, a fulcrum eccentric to the center of the plate between the intake and discharge ports of the plate on the compression side of the pumping means for establishing a sealing engagement of the plate and easing arouiid the inlet port of the casing, and packing rings between the plate and the wall of the casing.

11. A rotary pump comprising a casing containing a pumping chamber and having an intake thereto and discharge therefrom, intermeshing pumping gears with cavities between the teeth of said gears, rotatable in said chamber, and means movably located in said chamber adjacent to and bearing against the side faces of said-gears only, said means closing one end of said cavities and being exposed to the fluid discharge pressure and forced thereby against the aces of both gears for closing and preventing leakage from one cavity to another across the gear teeth.

12. A rotary pump comprising a casing containing a pumping chamber and having an intake thereto and discharge therefrom, rotatable pumping elements in said cham her, and a loosely retained valve plate locat ed adjacent to the side faces of the pumping elements, which plate is exposed to the discharge pressure in the pumping chamber and forced thereby against the faces of the pumping elements.

EBENEZER HILL;

ice 

